The Zalando Multi-country channel gives you the option to select in which countries you wish to publish your products, using one unique feed.
In your Lengow billing plan, each activated sales channel counts as one marketplace.
At the "Multi-feed" step, select one or more sales channels (= countries).
As a result, Lengow will display the attributes specific to these countries. Examples: "quantity_es", "regular_price_de", etc.
Zalando must authorize you to publish on these sales channels for them to be available in Lengow.